光纤陀螺仪自动测试系统设计

为了满足多种型号光纤陀螺仪的复杂测试需求,该文设计了一种光纤陀螺仪自动测试系统。该测试系统具有基于FPGA的硬件主板与模块化可更换的陀螺仪电源、信号采集子板,支持多串口测试协议,采集的数据通过串口转换后统一发送到上位机软件端进行存储、分析和显示,可导入模板实现测试、参数标定全程自动化,并生成统计报表。该系统遵循GJB 2426A—2004标准,能兼容市面90%以上的各型光纤陀螺仪,可自动化完成光纤陀螺仪的基本性能测试,大大提升产品研发检测的效率。     

基于Verilog HDL的三轴光纤陀螺时分复用系统数字滤波电路的实现

随着光纤惯性导航系统和光纤陀螺小型化技术的发展,开展三轴一体化光纤陀螺的研究是当前的一个主流。文章首先介绍了三轴一体化光纤陀螺时分复用技术方案,基于FPGA器件,运用Verilog HDL实现梳状滤波功能,完成了三轴一体化光纤陀螺时分复用系统数字滤波电路的设计,减小了电路系统的体积,降低了功耗,满足系统要求,实现了系统的小型化。     

微机械陀螺非线性特性的自由衰减振荡测量方法

针对微机械陀螺非线性特性的测量问题,研究了一种频率步进式正弦脉冲激励的自由衰减振荡测量方法。在谐振频率附近,采用步进式正弦脉冲序列作为激励信号,得到一组包含系统不同程度非线性动力学特征的自由振动响应信号。通过Hilbert变换提取自由振动信号的瞬时幅值和瞬时频率,计算得到骨架曲线簇,即可实现非线性动力学特性的实验测量。以Duffing系统为例,对不同信噪比自由振动响应信号进行了数值仿真,结果表明这种方法比FREEVIB方法具有更好的抗噪声性能。对一种环型振动微陀螺进行了实验测试,所得到的骨架曲线与传统扫频方式的测量结果一致。作为一种测试手段,这种方法同样可用于其他类型微机械谐振器动力学特性的实验测试。     

利用负刚度效应调谐的硅调谐式陀螺仪

为了验证硅调谐式陀螺仪原理的可行性,研究了硅调谐式陀螺仪的调谐机理,硅转子运动模态和加工工艺以及信号检测与再平衡控制回路。提出了一种利用力矩器的负刚度效应来实现硅调谐式陀螺仪调谐的新方法,推导了静电负刚度调谐的理论公式;设计、仿真、加工了硅薄片式转子平衡环部件和电容器极板,给出了电容信号敏感接口电路、升压放大电路、反馈校正电路和再平衡控制回路。在此基础上,实现了硅调谐式陀螺仪原理样机。试验结果证实,利用负刚度效应调谐是可行的,接口电路和再平衡控制回路设计是合理的。初步性能测试表明,硅调谐式陀螺仪可实现标度因数为1.42mV/((°)/s),标度因数非线性为2.47%,量程为±200(°)/s。试验结果验证了该陀螺仪基本原理的可行性。     

Angular velocity calibration system with a self-calibratable rotary encoder

Gyroscopes are essential components of electronic stability control systems (ESC), which are currently incorporated in automobiles to reduce car accidents. To meet the traceability requirements of gyroscopes in ESC testing system, a novel type of angular velocity calibration system was developed at the National Metrology Institute of Japan. The system is equipped with a self-calibratable rotary encoder (SelfA), operating on the same self-calibration principle as the national angle standard in Japan. To evaluate the performance of the system, the stability of the measured angular velocity was examined in both time domain and in terms of Allan variance. The noise effect from the slip ring was also measured. The calibration procedure was demonstrated by monitoring the response of a fiber-optic gyroscope from −180°/s to 180°/s at 30°/s intervals. The results confirmed that the system performance satisfies the requirements for angular velocity calibration of mid-performance MEMS gyroscopes.     

光纤陀螺全数字信号处理技术研究

信号处理技术在光纤陀螺向实用化发展的过程中起着重要作用。本文给出了一种基于ＤＳＰ的全数字信号处理方法。该方法不仅提高了开环光纤陀螺系统的动态范围,而且很好地解决了光纤陀螺的漂移问题。     

陀螺检测仪设计

以ARM7微处理器为核心,设计了一种体积小、数据存储量大、成本低、可靠性高的陀螺检测仪,设计中对电路的可靠性和陀螺信号的失真问题做了处理,能够满足中级精度以下的多种陀螺检测,实用性强,操作简单。软件具有数据存储和回放功能,方便日后查看研究。文章最后给出了检测仪的测量误差。     

微小光学器件装配系统与实验研究

在激光陀螺谐振腔上精确装配微小光学器件合光棱镜和光电管的过程称为合光,它是激光陀螺制造过程中的关键环节。传统的人工合光装配效率低、质量一致性差,已不能满足激光陀螺的生产需求。因此,本文在分析合光原理的基础上,开发一套由合光机构、信号处理、视觉检测及控制模块等组成的自动合光装配系统。根据合光装配特点,设计了双臂协同运动的合光机构,保证操作精准度的同时提高装配效率。激光陀螺合光信号易受干扰,提出采用Sallen-Key低通滤波器对合光信号进行滤波处理,有效地滤除了残杂噪声。控制模块通过机器视觉辅助完成合光棱镜的粗调,采用层次分析法综合多个评价参数确定光学器件的最佳位姿,实现合光装配自动化。试验结果表明,开发的激光陀螺合光装配系统能够成功地完成光学器件的精确装配。     

数字闭环干涉式光纤陀螺的控制器设计与仿真

光纤陀螺与传统的机械陀螺相比,具有动态范围大、成本低、体积小、可靠性高等优点.数字闭环干涉式光纤陀螺(IFOG)的动态性能受控制系统设计的影响.现根据光纤陀螺数字闭环检测过程,建立了控制系统的数学模型,设计了模糊自适应PID控制器.仿真结果显示,设计的控制器能够有效地增强系统的鲁棒性,缩短调节时间,改善系统的动态性能.     

双质量块调谐输出式硅MEMS陀螺仪

硅MEMS陀螺仪成本低、体积小、功耗低,是微小型无人系统及制导武器的核心惯性器件,本文提出一种双质量块调谐输出式硅MEMS陀螺仪,采用两块反相、同频、等幅振动质量块作为敏感单元,通过测量谐振器谐振频率变化来计算转速的大小,通过动力学分析,推导了哥氏力与输入转速的传递函数,用瑞利－里茨法求得在轴向力作用下梁的固有频率方程,利用马蒂厄方程分析了双端音叉谐振器的运动数学表达式及陀螺仪标度因数方程。最后利用ANSYS有限元软件对谐振器进行了稳定性及有预载荷的模态分析,验证了理论推导的正确性。该陀螺仪通过端部支撑结构将两质量块的振动能量相互抵消,减少了振动噪声及能量损耗,利用杠杆反相差分效应,消除了外界加速度引起的误差。     

光纤陀螺技术研究

阐述了光纤陀螺研制中的主要技术问题和陀螺样机的研究结果。借助琼斯距阵 ,建立了光纤陀螺偏振过程模型 ,导出了陀螺输出表达式 ,阐明了提高陀螺性能的主要技术关键问题。对庞加球 ( Poincare)也作了同样的说明     

微小型光纤陀螺组合分时复用技术

为了有效减小多轴光纤陀螺组合的功耗、体积和重量,实现光纤陀螺组合的微小型化,应用分时复用技术,提出了一种基于3×3耦合器,工作在850 nm短波长的光纤陀螺分时复用组合结构。分析了陀螺输出数据处理方法,得到了分时复用光纤陀螺组合的相对极限零偏稳定性。建立了分时复用光纤陀螺切换模型,揭示了分时复用导致光纤陀螺轴向切换必然存在一个过渡过程,分析了过渡过程对陀螺组合静态、动态特性的影响。结果显示,光纤陀螺组合的相对零偏稳定性是传感方法的2.1倍,最大输入信号检测带宽为1.1 kHz,标度因数的不对称性和非线性度均小于50×10-6。最后,通过仿真进行了实验验证,结果表明,该技术可以用于中低精度微小型多轴光纤陀螺组合中。     

Design and Fabrication of MEMS Gyroscopes on the Silicon-on-insulator Substrate with Decoupled Oscillation Modes

The mode coupling is a major factor to affect the precision of the micro electromechanical systems(MEMS) gyroscope. Currently, many MEMS gyroscopes with separate oscillation modes for drive and detection have been developed to decrease the mode coupling, but the gyroscope accuracy can not satisfy the high-precision demand well. Therefore, high performance decoupled MEMS gyroscopes is still a hot topic at present. An innovative design scheme for a MEMS gyroscope is designed, and in this design, the inertial mass is divided into three parts including the inner mass, the outer mass and the main frame mass. The masses are supported and separated by a set of mutually orthogonal beams to decouple their movements. Moreover, the design is modelled by multi-port-element network(MuPEN) method and the simulation results show that the mode coupling of the gyroscope between driving and sensing mode was eliminated effectively. Furthermore, we proposed a new silicon-on-insulator(SOI) process to fabricate the gyroscope. The scale factor of the fabricated gyroscope is 8.9 mV/((o)?s) and the quality factor(Q-factor) is as high as 600 at atmosphere pressure, and then, the resonant frequency, scale factor and bias drift has been test. Process and test results show that the proposed MEMS gyroscope are effective for decrease mode coupling, furthermore, it can achieve a high performance at atmosphere pressure. Furthermore, the MEMS gyroscope can achieve a high performance at atmosphere pressure. The research can be taken as good advice for the design and fabrication of MEMS gyroscope, meanwhile, it also provides technical support for speeding up of MEMS gyroscope industrialization.     

残余应力对z轴硅微机械振动陀螺仪性能的影响

z轴硅微机械陀螺仪采用体硅薄片溶解法制作,在加工过程中引入了残余应力。从理论上分析了残余应力对z轴陀螺仪工作模态的影响,并采用有限元软件进行了仿真。仿真结果和试验表明,第一回合设计的z轴陀螺仪驱动轴受到张应力作用,应力值约为20～30MPa;检测轴受到压应力的作用。在此基础上提出了两种应力释放结构的设计方案,折叠梁结构的设计和应力释放槽的开设。由第二回合设计的z轴陀螺仪试验结果表明,陀螺仪结构内残余应力得到了较好地释放,大大提高了陀螺仪结构的机械灵敏度。     

光纤陀螺在摇摆状态下的误差特性分析

在海上由于风浪的作用船用光纤陀螺经常处于摇摆状态.在这种运动状态下,光纤陀螺的误差严重制约着捷联惯导系统的导航精度.根据光纤陀螺闭环控制系统的原理,建立了系统模型,并推导出光纤陀螺在摇摆状态下的附加相移误差(实际与理想状态之间闭环控制附加相移的差)表达式和输出误差表达式.从两式可以看出,附加相移误差影响系统的回路平衡时间和输出精度.详细剖析了附加相移误差表达式中各参数所代表的意义以及作用于附加相移误差的途径,并给出减小附加相移误差的方法.仿真和实验结果证明理论分析准确可信,为光纤陀螺动态方面的研究提供了参考.     

Characterization of whispering gallery mode slow light in microspheres

A slow-light system composed by a microsphere resonator and a section of bitapered fiber is characterized theoretically in this article. Theoretical analysis and numerical simulation on the input and output characteristics and the transmittivity of the microsphere resonator were carried out. The directional coupling theory was used to analyze the input/output characteristics of single microsphere resonator and parameters in the overcoupling state, including the relationships between the effective phase shift, transmittivity, effective time delay, light velocity, and the speed of light. The coupling coefficient distance was studied by theoretical analysis and numerical simulation. The theoretical analysis and simulation optimization of the slow-light gyroscope were carried out to obtain the optimized radius of microsphere resonator and distance between microsphere resonator and bitapered fiber. Through theoretical investigation and mathematical simulation, transmission characteristics and time delay mathematical expressions of the microsphere resonator were obtained. Theoretical analysis and simulation of the fiber optic gyroscope sensitivity showed that slow-light improved the accuracy of the interferometric fiber optic gyroscope.     

Development of a three-axis acceleration signal measurement system for fMRI motor studies

The purpose of this study was to develop a three-axis acceleration signal measurement system that could measure acceleration signals without deteriorating the functional magnetic resonance imaging (fMRI) data and not affect the main magnetic field, the gradient magnetic field, which varies rapidly with time, or the radio frequency (RF) pulse during fMRI acquisition. A three-axis accelerometer was used to measure acceleration signals, and Velcro was used to attach the accelerometer module to a finger or wrist. To minimize the mutual interference effect between the fMRI system and the acceleration signal measurement system, an amplifier circuit was constructed of analog devices, and the amplifier was located in the shielded case, which was made of copper and aluminum. The acceleration signal was modulated to an optic signal using pulse width modulation (PWM), and the modulated optic signal was transmitted outside the fMRI room using a light emitting diode (LED) and optic cable. We were able to verify that fMRI data and the tri-directional acceleration signal were measured simultaneously and stably. Various movement variables such as position, velocity, and jerk could be obtained numerically. Therefore, this system could be used for studying of the relationship between various movement variables and brain motor function, especially for the study of the rehabilitation field.     

Digitalization optical open loop test system for fiber optic gyroscope

In order to receive and process the open loop signal from fiber optic gyroscopes speedily, stably and expediently, and to realize the amity interface between human and machine, a digital system that can convert GPIB (general purpose interface bus) parallel bus into Universal Serial Bus is developed. All the interface functions of GPIB and the hardware system are realized through FPGA. With a digital sampling and processing system designed with VC++ in Windows platform, the real-time controlling procedure, high-speed receiving and sending data can be carried out, and the results can be displayed too. So the design of the system is flexible, the reliability and the stability are improved, error rate is no more than 10⁻¹¹, the highest bit rate is 8 MB/s and the open loop detection system for optic fiber gyros achieves standardization and complete digitalization simultaneously. __________ Translated from Chinese Journal of Scientific Instrument, 2005, 26(10) (in Chinese)     

MEMS陀螺与编码器在机器人自主定位中的应用

为提高微机械陀螺仪输出精度及移动机器人定位精度,研究了基于微机械陀螺仪与光电编码器的移动机器人自主定位方法。实时小波滤波法算法去除微机械陀螺仪输出数据噪声;通过微陀螺精度校正平台,用加权最小二乘支持向量回归机算法对微机械的先验数据作回归运算,构造先验回归决策函数,运用回归决策函数补偿微机械陀螺仪输出误差,提高微机械陀螺仪的角速率输出准确度;实验证实了方法能较好提高了MEMS陀螺仪的准确度,可以应用于移动机器人的自主定位之中。     

振动轮式微机械陀螺动态特性光学测试方法研究

振动轮式微机械陀螺尺寸小、振动频率高,为了精确评价其动态特性,建立了基于高速摄像技术、显微技术与数字图像相关技术的光学测试系统。配有光学显微镜的高速摄像设备(32000fps)记录并保存被测物瞬时序列图像,根据被测物的角振动特性设计相应的图像相关计算方法以获得振子各时刻的运动位移,并通过位移时间曲线分析振子的固有频率、阻尼系数及品质因子等动态特性参数。实验结果显示,图像相关精度达0.01像素,频率测量误差小于0.01%。高精度地测量了振动轮式微机械陀螺的动态特性,为微结构动态特性的研究提供了一个有效方法。